The present invention relates broadly to the collection of urine output from hospital patients and for the measuring and monitoring of total urine output and urine flow rate. Conventionally, urine collection bags are routinely used for post-operative patients as well as those suffering from urological disorders. In use, the patient is first catheterized and the distal catheter end is then connected to the drainage bag through a length of tubing. The bag is normally suppported below the patient either from the bedrail or other support and the urine will drain by gravity from the patient through the catheter, the tubing and then finally into the bag.
Many of the prior art urine bags are provided with printed scales in the form of lines on the face of the bag to permit coarse visual monitoring of urine output. It is of course even possible with such bags to measure flow rate by use of a stop watch or other timing devices to measure the time interval between commencement of the sampling and the time when the urine level reaches a certain predetermined height in the bag and to then make appropriate calculations. An early example of a meter bag for urine is the U.S. Pat. No. 3,345,980 to Coanda. In this construction, urine flows from a catheter into an elongated rigid meter, the lower end of which connects to a separate storage container. A pinch valve prevents transfer of urine to the container until desired, and a meter overflow line is also provided. A somewhat more sophisticated arrangement is shown in Holbrook et al, U.S. Pat. No. 3,776,231, which discloses the use of two rigid containers located in tandem with a pivot valve joint to permit transfer of urine from a calibrated meter to a storage chamber. Using this arrangement, the ability to measure flow rate is simplified yet it still requires the presence of trained personnel and the use of a hand timer or the like, and of course calculation.
The present invention overcomes many of the problems in the prior art and provides automatic electronic means for measuring both total urine output as well as flow rate without constant monitoring by trained hospital personnel. The invention finds great utility in coronary care units, intensive care units, the treatment of burn patients, and for patients with kidney or other renal operations.
The principal advantages of the present invention over the known prior art are the increased accuracy of the measurements and the obviation of the necessity for utilizing trained personnel to constantly monitor and time flow operations. Further, problems in reading the scales on previous urine meters, including parallax errors, are not present.
Additionally, with the device of the present invention, it is not necessary for the monitoring unit to be installed on or adjacent the hospital bed with particular care as to alignment, since the device is designed to operate even under conditions of rather extreme misalignment from the vertical. It is not necessary for the hospital personnel to make any calculations or to do any timing whatsoever, all calculations being performed by the circuitry and digitally displayed on an easy-to-read monitor console. Further, if desired, alarm means may be provided on the console to give an indication of either low or high urine flow rates.